With the proliferation of the World Wide Web and data networks such as the Internet, consumers often turn to their computers when searching for information relating to products or places, rather than using traditional printed directories. Providers such as online search engines, directories of advertisers, and the like, often charge advertisers to have listings included in a set of search results. In some instances, an advertiser pays for a listing or an advertisement to be displayed on a webpage that does not include a set of search results. In this case, an advertiser is charged simply for having the advertisement displayed on the webpage. Further, advertisers are often charged on a per-click basis, meaning that every time an online user clicks on an advertisement, the advertiser is charged. A provider may wish to display listings in a manner to maximize its own revenue as well as provide greater benefit to advertisers.